Novel catalyst support

ABSTRACT

THE DISCLOSURE PROVIDES A NOVEL CATALYST SUPPORT, A METHOD OF MAKING SAID SUPPORT BY TREATMENT OF PRIOR ART CRYSTALLINE CATALYST SUPPORT WITH HYDROXY-ALUMINUM SOLUTION AND HYDROCARBON CONVERSION PROCESSES WHEREIN THE CAATALYST USED THEREIN INCLUDES SAID SUPPORT.

United States Patent cc 3,798,177 NOVEL CATALYST SUPPORT Marion G. Reed, Hacienda Heights, and Joseph Jalfe,

Berkeley, Calif., assignors to Chevron Research Company, San Francisco, Calif. No Drawing. Filed Sept. 3, 1971, Ser. No. 177,819 Int. Cl. B01j 11/40 US. Cl. 252-455 R 14 Claims ABSTRACT OF THE DISCLOSURE The disclosure provides a novel catalyst support, a method of making said support by treatment of prior art crystalline catalyst supports with hydroxy-aluminum solution and hydrocarbon conversion processes wherein the catalyst used therein includes said support.

BACKGROUND OF THE INVENTION The invention relates to a method of treating a crystalline catalyst support whereby its structural and catalytic properties are improved. The method comprises contacting the catalyst support with a hydroxy-aluminum solution having a ratio of hydroxyl groups to aluminum atoms in the range from about 1.5 to about 2.7.

Catalyst support materials are useful for a numberof processes, particularly such supports are useful for hydrocarbon conversion processes. Typical processes are hydrocracking, catalytic cracking, reforming, hydrofining, isomerization, dewaxing and the like. The catalyst art always needs new and useful catalyst supports or carriers.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a novel catalyst sup! port, hydrocarbon conversion processes using saidnnovel catalyst support, and a method for preparing this 'novel catalyst support. The novel catalyst support comprisesa crystalline catalyst support of the prior art which has been treated with a hydroxy-aluminurn solution having a ratio of the hydroxyl groups to aluminum groups within the range from about 1.5 to about 2.7, and preferably 2.0 to 2.4. The process for preparing a novel catalyst support comprises treating a crystalline catalytic support of the prior art with a hydroxy-aluminum solution having a ratio of hydroxyl groups to aluminum atoms within the range from about 1.5 to about 2.7.

GENERAL DESCRIPTION OF THE INVENTION The crystalline catalyst supports of the prior art may be benefited by treatment with a hydroxy-aluminum solution as set out herein. In particular, natural and synthetic layered clay-type mineral catalyst supports and natural and synthetic crystalline zeolitic molecular sievetype catalyst supports can be benefited through reaction with the hydroxy-aluminum solution. Non-crystallinesupports, such as amorphous silica-alumina, may also be benefited through being contacted with a hydroxy aluminum solution to form a novel catalyst composition of matter. However, it is generally preferred that the catalytic carrier which is improved by treatment with a hydroxy-aluminum solution be a crystalline catalytic material. v

The hydroxy-aluminurn treatment of catalyst supports of the prior art stabilizes the crystalline structures of the 3,798,177 Patented Mar. 19, 1974 catalyst support material; for example, when natural or synthetic clay materials are treated with the hydroxy-aluminum solution as disclosed by the present invention, the clay layers become held at substantially a constant separation from one another and the clay minerals do not expand upon exposure to water. Thus, for example, successive smectite, and in particular montrnorillonite layers which have been treated with the hydroxy-alurninum solution exhibit a basal separation of about 15 angstroms as determined by X-ray diffraction and this 15 angstrom separation is retained even when the montrnorillonite clay mineral is exposed to water. The basal separation is the distance between successive repeating clay layers as shown by X-ray diffraction. This is in sharp contrast to montrnorillonite which has not been treated with a hydroxyaluminum solution wherein exposure to water will lead to a large change in the separation of the successive montmorillonite layers from one another. Although not meaning to be bound by theory, it is believed that the hydroxyaluminum solution treatment of crystalline material leads to the formation of gibbsite-like layers between the crystalline layers of the catalyst support material.

In some cases, it is desirable to treat a catalyst support material with the hydroxy-aluminum solution by the method of the present invention so as to expand the support so that it will have desirable surface area and pore diameter properties for any particularly desired catalytic application.

The hydroxy-aluminum treated crystalline catalyst support is aged in water, preferably pure water, for at least 3 hours and preferably for about 24 hours. Aging is beneficial because it allows the adsorbed hydroxy-aluminum to polymerize. The larger polymerized species are more resistant to exchange reactions and provide more strength to the support.

In a typical application, a crystalline catalytic support is treated with a solution formed by mixing water first with a quantity of aluminum salts selected from the group consisting of aluminum chloride, aluminum bromide, aluminum iodide, aluminum nitrate, aluminum sulfate and aluminum acetate. The selected salt is added in an amount of between 0.01 and 24.0 pounds of aluminum per 42 gallons of water (i.e., oil barrel) to form an aluminum solution. To this aluminum solution is added an alkali, alkaline earth, ammonia or substituted ammonia base in an amount from 0.95 to 1.7 pounds of hydroxyl ion for each pound-of aluminum to form a hydroxy-aluminum solution. The aforesaid hydroxy-aluminum solution is formed in the manner hereinafter described in a suitable mixing tank and is then contacted with a crystalline catalyst base. The resulting catalyst base may be improved over catalyst base which has not been treated with a hydroxy-aluminum solution, in particular the stability and strength of the catalyst base may be improved.

After contact with the hydroxy-aluminum solution, the catalytic support or carrier can be dried and calcined by the usual methods of the prior art. If desired, catalytic promoters can be included herewith.

The amount ofthe hydroxy-aluminum solution that should be used in treating the crystalline catalytic support may. vary within wide limits depending upon the particular reaction which the support is being prepared to catalyze. Generally, greater than 10 percent of the exchangeable cation capacity of the crystalline catalytic support will be replaced by the hydroxy-aluminum species.

The surface area of the resulting catalyst can be ad jiisted as necessary by several means such as varying the area of the support to be treated, varying the treatment dosage and varying the calcination conditions. Generally a surface area of above 50 m. g. is preferred. Generally, the surface area would not exceed about 750 mP/g. and more preferably would not exceed about 500 m. g.

When the improved catalytic support of the present invention is to be used for catalytic cracking, hydrocracking and/or isomerization processes, it is preferred that it have a surface area about about 200 m. /g., and preferably within the range of about 300 to about 500 m'. g. Conventional hydrogenative components are included with the support for most applications other than catalytic cracking. Any hydrogenating component may be used.

For example, hydrogenating components of Groups IV,

V, VI, VH, and VIII of the Periodic Table are useful alone or in combination with each other. The particular hydrogenating component chosen will depend on the particular reactions that it is desired to promote. Those skilled in the art are aware of which hydrogenating components are most useful for which reactions.

When the novel support of the present invention is to be used, for example, for demetallation, desulfurization or hydrocracking of heavy petroleum fractions such as residua, the catalytic components, which may exist as metals or compounds, e.g., oxides, sulfides, fluorides or the like are preferably at least one of nickel or cobalt along with at least one of molybdenum or tungsten, or more generally a Group VI component associated along with a non-noble metal of Group VIII. The surface area of catalysts used for demetallation, desulfurization and hydrocracking of heavy feedstocks is preferably within the range from about 100-200 m. /g. with average pore diameters in the range of 100-1000 angstrom units.

In one particularly preferred embodiment the hydroxyaluminum solution is produced from aluminum chloride and ammonium hydroxide. The solution is prepared by partially neutralizing an aluminum chloride. solution with ammonium hydroxide with agitation. Aluminum chloride hexahydrate may be dissolved in an amount of 8.7 pounds per barrel of water by slow addition to water. After thealuminum chloride solution is prepared, ammoniumhydroxide in an amount of 2.6 pounds per barrel maybe slowly added to the solution at the point which will provide the best mixing and at a rate such that all will be added in from generally about 30 minutes to about 1 hour. The mixture will cloud during the addition of hydroxide due to the formation of a precipitate. However,

the solution will clarify in time depending on the temper ature of the aluminum concentration, the stirring vigor and the rate of addition of hydroxide solution.

The clear hydroxy-aluminum solution may be used directly to treat catalyst supports, and more particularly, crystalline catalyst supports .to produce novel and improved catalyst supports.

Another method for making the hydroxy-aluminum solution of the invention, and in fact a preferred method, is to bring together solutions of an aluminum salt and ammonia, or substituted ammonia, an alkali, or an alkaline earth base, in a high shear zone. In the preferred form the hydroxy-aluminum solution is prepared in a high shear mixer by proportion mixing of aluminum chloride and ammonium hydroxide solutions. The hydro-xy. aluminum solution may be prepared in any concentration below its saturation value. However, a X concentrate containing about 97 lbs./bbl. equivalent A1Cl (275 g l.) is the most practical. This concentrate is diluted 20 fold prior to application to a crystalline catalytic support. The exact quantities of the aluminum chloride and hydroxide solutions will depend on their concentration, purity and the desired OH/Al ratio of the product.

I ar/98,177

EXAMPLE As an example of a catalytic support prepared in accordance with the present invention, the following procedure can be carried out.

About grams of montmorillonite clay in the ammonium" form and having a silica/alumina ratio of about 2.2 can be blended in a Waring Blender or the like with about 2 liters of water. And about 0.1 molar hydroxyaluminum solution can be added to the water-clay blend in suflicient amount to provide at least 0.1 mole of hydroxy-aluminum per cation exchangeable equivalent of the clay. The solution is then blended for a short time. The clay after contact with the hydroxy-aluminum' solution'will flocculate readily. After flocculation, the clay is removed from the solution byv filtration and is suspended in fresh water (about 2 liters). The slurry is allowed to age for about 24 hours.

The aged hydroxy-aluminum treated clay slurry is refiltered. The filter cake is impregnated with catalytic meta-ls either in the nascent wet state or after drying, using well-known procedures.

The catalytic component used can preferably be palladium or other metals of Group VIII in a concentration of typically about 1 to 10 percent calculated as the metal. If the catalytic component is a noble metal of Group VHI, and more particularly if it is palladium, the preferred amount is about 0.2 to 1 percent.

The impregnated catalyst support is calcined to activate it. The resultant catalyst is useful for hydrocrac-king, hydroisomerization and the like.

T From the above description it is evident that the invention provides a novel catalyst support and a method of making this novel catalyst support, as well as hydrocarbon conversion process using said novel catalyst support. Although only specific embodiments of the present invention have been described above, the invention is not meant to be limited thereto, but is meant to includeall embodiments coming within the scope of the appended claims.

What is claimed is:

1. A method of improving the structural stability of a crystallinesilica-alumina catalyst support, consisting essentially of contacting the catalyst support with a hydroxyaluminum solution, containing hydroxyl ions and alumi-' num ions and wherein the ratio of hydroxyl ions to aluminum ions in said solution is within the range from about 1.5 to about 2.7.

2. A method as in claim 1 wherein the ratio of hydroxy ions to aluminumions is from 2.0 to 2.4.

3. A method as in claim 2, wherein the hydroxyaluminum solution is about 0.1 molar.

.4. A novel composition of matter produced by the method of claim 1.

5. A composition of matter produced by the method of claim 2.

6. Acomposition of matter produced by. the method of claim 3. V

7. A method of making a crystalline silica-alumina catalyst support, consisting essentially of:

(l) contacting the crystalline silica-alumina catalyst support in an aqueous slurry with hydroxyaluminum solution having a ratio of hydroxyl groups to aluminum atoms from about 1.5 to 2.7, to form a coherent porous mass,

(2) aging said porous mass in water for at least about 3 hours, and removing said mass from said water.

8. A method as in claim 7, wherein the aging in water is for about 24 hours.

9. A method as in claim '7, wherein the ratio of hydroxyl groups to aluminum atoms is from 2.0 to 2.4. '10.'A method as in claim 9, wherein the hydrox aluminum solution is 0.1 molar.

11. A method in accordance with claim 1 wherein the References Cited catalyst support is a crystalline silica-alumina layered UNITED STATES PATENTS clay. 2,285,314 6/1942 Thomas et a1. 252-455 R X th d 1 7 th 2,410,436 11/1946 Ewing 423112 X 12 A me 0d 1n accor ance w I arm \iavherern e 5 3,562,148 2/1971 Mitsche 252-455 Z catalyst support is a crystalllne silica-alumina layered 3,607,043 9/1971 McDaniel et aL clay.

.13. A composition of matter produced by the method PATRICK GARVIN Primary Exammer of claim 11' 10 A. H. METZ, Assistant Examiner 14. A composition of matter produced by the method US. Cl. X.R.

of claim 12. 252-455 Z; 423112, 118, 328, 329 

